There is overwhelming scientific evidence that man-made chemicals
are destroying the ozone layer -- Nobel prizes have already been awarded
for the research. Rush Limbaugh argues that humans are safe, because volcanic
chlorine has been working on the ozone layer longer than man-made chlorine,
and yet we're still here. But this argument is false. Volcanic chlorine
is water soluble, and rained harmlessly out of the atmosphere. Human CFCs
are insoluble, and can therefore rise to the ozone layer where they can
do their damage.

Argument

Do man-made chlorofluorocarbons (CFCs) destroy the ozone layer?
There are no longer any skeptics left at NASA, the National Academy of
Sciences, the National Center for Atmospheric Research, or the World Meteorological
Organization. In fact, the three scientists who first sounded the alarm
in the early 80s -- F. Sherwood Rowland, Paul Crutzen and Mario Molina
-- received the 1995 Nobel Prize in chemistry for their work.

In 1991, NASA launched the Upper Atmosphere Research Satellite (UARS)
in an attempt to determine once and for all if humans were responsible
for causing this serious damage to the atmosphere. The data relayed back
to NASA clinched the matter beyond all reasonable doubt. "There is
a very clear link between man-made chlorofluorocarbons (CFCs) and destruction
of the ozone layer," says Dr. Aidan Roche, the Lockheed scientist
whose team analyzed the satellite data for years. (1)

In one paragraph, the process works this way. The ozone layer is a
thin, protective layer of the stratosphere, which rises 12 to 15 miles
high. It shields the earth from the sun's ultraviolet rays, which are deadly
to most life forms. Unfortunately, ozone can be destroyed by chlorine radicals.
The earth naturally produces chlorine radicals, especially from volcanic
eruptions, but because they are water soluble they are safely rained out
of the atmosphere. However, man-made CFCs are not water soluble. CFCs are
free to rise all the way to the top of the stratosphere, where they break
down, releasing their chlorine radicals. The reaction is complex, involving
many different chemicals, but the result of these reactions is that the
CFC is recreated, allowing it to continue wreaking havoc. Other
processes are at work to remove CFCs from the ozone layer, so these reactions
really can't continue indefinitely, but scientists expect the CFC's already
present to remain there for the next century. In fact, recent measurements
show that the level of CFCs is already declining, thanks to international
treaties banning their production. (2)

The banning of CFCs is a triumph of both science and international
diplomacy. In the early 80s, scientists working in the Antarctic noticed
that there was a hole in the ozone layer over the South Pole. Preliminary
research pointed to CFCs as the culprit. In October 1987, the world's nations
signed the Montreal Protocol, pledging to cut CFC production in half over
the next ten years. Subsequent scientific evidence suggested the threat
was worse than realized, and the Protocol was strengthened twice - once
in London in 1990, and again in Copenhagen in 1992. The Copenhagen agreement
moved up the complete ban of CFCs to January 1996. Today, they are completely
outlawed, although they can still be found on the black market.

And speaking of markets, one might presume that the chemical industry
fought the ban tooth and nail. Actually, the industry's response was mixed.
When the evidence was still preliminary and debatable, the chemicals companies
furiously resisted any notion of a ban. But as the scientific evidence
grew stronger, the industry reasonably concluded that it could not be seen
defending profits from a product that threatened to destroy all life on
the planet. In fact, Dupont proposed a global ban of CFCs before the governments
of Europe and the United States did. (3) There was a self-interested motive
in this, however; a global ban of CFC's would create a global need for
a replacement, and Dupont was the best positioned to develop and market
the first one. Even so, many find industry's rapid agreement to the ban
heartening, although some watchdog groups, like Ralph Nader's Public
Citizen, have chronicled many cases of industrial foot-dragging.

Interestingly, the greatest opposition to the scientific evidence came
not from industry, but from the party of industry: the Republicans. During
the 1992 presidential campaign, President George Bush contemptuously referred
to Al Gore as "ozone man." Vice-president Dan Quayle called Al
Gore's environmental bestseller, Earth in the Balance, a "strange
manifesto." But perhaps no one has carried the ideological war to
the atmospheric scientists quite like Rush Limbaugh. His is probably the
most infamous factoid of the ozone debate: the volcanic eruption of Mount
Pinatubo.

In The Way Things Ought to Be, Limbaugh wrote:

Mount Pinatubo in the Philippines spewed forth more than
a thousand times the amount of ozone-depleting chemicals in
one eruption than all the fluorocarbons manufactured by wicked,
diabolical, and insensitive corporations in history. So much so that
respected scientists now say that a 4 percent to 6 percent ozone loss
could -- could, but may not -- occur over the Northern Hemisphere
in the next two or three years... volcanoes have been doing this for
4 billion years. And guess what? We still have a healthy ozone layer! (4)

Of course, anyone familiar with the CFC process described above knows
the flaw in this argument -- the chlorine spewed from volcanic eruptions
is water soluble, and washed harmlessly out of the atmosphere. No scientist
worth his salt would have made such a mistake, and no national news network
with even a rudimentary system of scientific review would have allowed
this fractured fact to be aired.

But Rush is -- all legal smoke and mirrors aside -- an employee of
ABC, and in its efforts to promote him, ABC arranged for Rush to appear
on Ted Koppel's Nightline to debate then-senator Al Gore on the
environment. Rush scored a clear victory in the debate with the following
unfactual surprise: "If you listen to what Senator Gore said, it is
man-made products which are causing the ozone depletion, yet Mount Pinatubo
has put 570 times the amount of chlorine into the atmosphere in one eruption
than all of man-made chlorofluorocarbons in one year." Notice that
Rush couldn't even keep his story straight; 1,000 is not 570, and "ever
in history" is not one year. Researchers checking up on his confused
story found that neither version was correct.

A look into Rush's sources quickly revealed a series of sloppy reporting
and fabricated evidence. (5) One of Rush's sources turned out to be a magazine
published by the followers of Lyndon LaRouche, the eccentric cult-leader
who often runs for president of the United States, and who believes the
Queen of England is masterminding a genocidal plot under the guise of environmentalism.

The "570" figure apparently comes from Dixy Lee Ray's book,
Trashing the Planet, an anti-environmental diatribe which Rush calls
"the most footnoted, documented book I have ever read." (Rush
may be impressed by multiple footnotes, but professional scientists find
them unremarkable, even routine). At any rate, Dr. Stephen Schneider, a
senior scientist at the National Center for Atmospheric Research, states
that Ray's book "was wrong on nearly everything." (6)

But when it came to using Ray's arguments, Rush misquoted her. Ray
did not say it was Mount Pinatubo that poured 570 times the chlorine into
the air, but Mount Augustine, a volcano that erupted in Alaska in 1976!
Furthermore, a check into Ray's sources revealed that she, too,
had misquoted her source. Her source was apparently a 1980 Science
magazine article, but that piece talked about an unimaginably powerful
eruption that had occurred in California 700,000 years ago. Clearly, Rush
didn't have the foggiest clue what mountain he was talking about.

The NASA satellite experiments permanently laid to rest any idea that
the chlorine ravaging the ozone layer was volcanic in origin. NASA scientist
Mark Schoeberl announced at a press conference: "The detection of
stratospheric fluorine gases, which are not natural, eliminates the possibility
that chlorine from volcanic eruptions or some other natural source is responsible
for the ozone hole." (7)